A rubber gasket to be disposed in a compressed state between separators of a fuel cell includes a sealing portion having a sectional shape of a two-projection structure with a first projection having a curved slope of a first curvature radius (D), and a second projection provided on the first projection and having a second curvature radius (H). A pedestal portion extends in a horizontal direction with a predetermined thickness continuously from a foot portion of the curved slope of the first projection and has a flat bottom surface.